Curvy roads and highways have been found in studies to be safer than straight ones. As an episode of Modern Marvels made the point, when the postwar United States attempted to mimic the German Autobahn by making the US highway system, in hindsight the approach of plowing through everything that was in the way of the freeway construction resulted in long, flat, straight stretches of road where drivers could become inattentive, distracted, and were more likely to fall asleep. In contrast, Germany made the Autobahn flow with the lay of the land rather than fight it, resulting in roads that were both scenic and conducive to alert driving.

Maintenance on the Autobahn is more stringent than in the US. Entire sections are replaced when cracks appear, rather than simple patches. Additionally, the roads are twice as thick as their US counterparts.

Germans also follow a concept known as "Rechtsfahren," which translates to "drive right", meaning slower traffic should (and in fact must, if I recall German traffic law correctly from my high school German class) stay to the right to allow faster traffic to pass on the left. You must move right if somebody wishes to go faster than you, and you may not pass on the right at all.

Meanwhile, as a firefighter, I've dealt with numerous motor vehicle accidents caused by drivers having fallen asleep at the wheel while cruising on one of our many straightaways here in Texas. Most of them categorically deny having fallen asleep, but a conscious or sober person doesn't just veer off the road or into oncoming traffic for no reason. They also don't just happen to miss the bridge they were about to drive over at 70 miles per hour.

When it comes down to it, I like the curves of the Autobahn far better than the straightaways of I-40 or I-5.